Reject re-defining identical uncommitted cc def

When user attempts to update an uncommitted chaincode definition
with identical content as before, endorser should fail the invocation.
Otherwise, it results in an empty wset, which would be validated
against LifecycleEndorsement policy by default, instead of the policy
of org's own implicit collection.

FAB-17371

Signed-off-by: Jay Guo <guojiannan1101@gmail.com>

core/chaincode/lifecycle/lifecycle.go

@@ -407,6 +407,30 @@ func (ef *ExternalFunctions) ApproveChaincodeDefinitionForOrg(chname, ccname str
 	}
 
 	privateName := fmt.Sprintf("%s#%d", ccname, requestedSequence)
+
+	// if requested sequence is not committed, and attempt is made to update its content,
+	// we need to check whether new definition actually contains updated content, to avoid
+	// empty write set.
+	if requestedSequence == currentSequence+1 {
+		uncommittedMetadata, ok, err := ef.Resources.Serializer.DeserializeMetadata(NamespacesName, privateName, orgState)
+		if err != nil {
+			return errors.WithMessage(err, "could not fetch uncommitted definition")
+		}
+
+		if ok {
+			logger.Debugf("Attempting to redefine uncommitted definition at sequence %d", requestedSequence)
+
+			uncommittedParameters := &ChaincodeParameters{}
+			if err := ef.Resources.Serializer.Deserialize(NamespacesName, privateName, uncommittedMetadata, uncommittedParameters, orgState); err != nil {
+				return errors.WithMessagef(err, "could not deserialize namespace %s as chaincode", privateName)
+			}
+
+			if err := uncommittedParameters.Equal(cd.Parameters()); err == nil {
+				return errors.Errorf("attempted to redefine uncommitted sequence (%d) for namespace %s with unchanged content", requestedSequence, ccname)
+			}
+		}
+	}
+
 	if err := ef.Resources.Serializer.Serialize(NamespacesName, privateName, cd.Parameters(), orgState); err != nil {
 		return errors.WithMessage(err, "could not serialize chaincode parameters to state")
 	}
@@ -423,7 +447,7 @@ func (ef *ExternalFunctions) ApproveChaincodeDefinitionForOrg(chname, ccname str
 		return errors.WithMessage(err, "could not serialize chaincode package info to state")
 	}
 
-	logger.Infof("successfully approved definition %s, name '%s' on channel '%s'", cd, ccname, chname)
+	logger.Infof("Successfully approved definition %s, name '%s' on channel '%s'", cd, ccname, chname)
 
 	return nil
 }

core/chaincode/lifecycle/lifecycle_test.go

@@ -662,7 +662,7 @@ var _ = Describe("ExternalFunctions", func() {
 			})
 		})
 
-		Context("when the sequence number already has a definition", func() {
+		Context("when the sequence number already has a committed definition", func() {
 			BeforeEach(func() {
 				err := resources.Serializer.Serialize("namespaces", "cc-name", &lifecycle.ChaincodeDefinition{
 					Sequence: 5,
@@ -743,6 +743,28 @@ var _ = Describe("ExternalFunctions", func() {
 			})
 		})
 
+		Context("when the sequence number already has an uncommitted definition", func() {
+			BeforeEach(func() {
+				err := ef.ApproveChaincodeDefinitionForOrg("my-channel", "cc-name", testDefinition, "hash", fakePublicState, fakeOrgState)
+				Expect(err).NotTo(HaveOccurred())
+			})
+
+			Context("when uncommitted definition differs from update", func() {
+				It("succeeds", func() {
+					testDefinition.ValidationInfo.ValidationParameter = []byte("more awesome policy")
+					err := ef.ApproveChaincodeDefinitionForOrg("my-channel", "cc-name", testDefinition, "hash", fakePublicState, fakeOrgState)
+					Expect(err).NotTo(HaveOccurred())
+				})
+			})
+
+			Context("when uncommitted definition is identical to update", func() {
+				It("returns error", func() {
+					err := ef.ApproveChaincodeDefinitionForOrg("my-channel", "cc-name", testDefinition, "hash", fakePublicState, fakeOrgState)
+					Expect(err).To(MatchError("attempted to redefine uncommitted sequence (5) for namespace cc-name with unchanged content"))
+				})
+			})
+		})
+
 		Context("when the definition is for an expired sequence number", func() {
 			BeforeEach(func() {
 				testDefinition.Sequence = 3